The invention concerns an apparatus for adsorption of molecules from a gaseous medium wherein only one two-way valve is used for selectively connecting the ducts of the chambers containing the adsorbents with the inlet and outlet ducts of an adsorption circuit and a regeneration circuit.
This type of device is for instance used for adsorbing humidity from air.
Usually air is dried by passing it through a chamber filled with an adsorbent such as silica gel or a molecular sieve. The air then passes its humidity to the adsorbent. As soon as the adsorbent has taken up a certain percentage of humidity, it must be regenerated. The simplest way to do this is passing air at a higher temperature of for instance 250.degree. C. through the chamber.
In this kind of device each chamber is then alternatingly connected with the adsorption circuit and with the regeneration circuit. In order to carry out the adsorption and regeneration without interruption it is necessary to employ at least two chambers. In order to alternatingly make the chambers either of the adsorption circuit or of the regeneration circuit operative, two-way valves are employed. The cost of these two-way valves however is comparatively high.
It has already been suggested to use a two-way valve having two relatively rotatable valve discs which turn about a common axis and of which one disc has openings for the inlet and outlet of the adsorption circuit and the regeneration circuit while the other disc has openings for the connection with the adsorption chambers. This prior art circuit has the two openings for the connection of one chamber in each case on different radii from the center and thus at a differential distance from the pivot of the valve discs. The exterior dimensions of the valve must therefore be comparatively large. A reduction of the size of the valve would result in a narrowing of the open cross section of the apertures of the discs. Furthermore it is impossible with this device to improve the adsorption and regeneration operation by connecting two adsorption circuits in a predetermined time and space relationship.
It is therefore an object of the present invention to provide an apparatus which permits use of a two-way valve of the type described which has comparatively limited exterior dimensions but nevertheless a comparatively large inside flow diameter. It is another object of the invention to provide this type of device for the connection of two adsorption chambers in the adsorption circuit.